UNDERSTANDING STRUCTURES

AND MECHANISMS-FLIGHT a review

Air is a gas and also is a fluid.It takes up space and fills the shape of the container it is placed in.

We demonstrated this with the two cups, one filled with air the other with water. We then transferred the air from one cupinto the other, displacing the water.

Air can exert a force when compressed remember when someone brokeThe syringe?

Know this

Air exerts pressure equally in all directions(unless an external force affects it). This pressure ismeasured in atmospheres. One atmosphere is equal to 1 kg per square cm or 14.7 pounds per square inch at sea level on Earth.

The blue bar representsOne atmosphere

Know this

Bernoulli’s Principle:

When you increase the speed of air over a smooth, hard, curved surface, you lower the pressure and generate lift.

Aerofoil or air foilKnow this

gravity

There are 4 forces that act on an aircraft:GRAVITY(weight/mass)- the attraction between the aircraft and the centre of the Earth.LIFT-upward force counteracting the pull of gravity and produced by the interaction of the wing and the air.THRUST-forward motion of the aircraft produced by some action such as a propeller spinning, a jet or rocket shooting gases out of itstail, or even a hand throwing the aircraft.DRAG-resistance of the air to an object moving through it.

Know this.Be able to

explain and label a

diagram

Know the followingParts of the airplane:Fuselage, rudder, ailerons,Elevators and how they affect the control of an airplane.

FuselageThe body of the plane

Flight without wings

All airplane designs depend on wings to provide lift.Obviously hot air balloons and lighter than air ships (blimps or zeppelins) produce lift by trapping gases which areless dense than the surrounding air in a container (nylon balloon)And they float in our atmosphere.

The problem with hot air balloons is that there is no control over the direction that the balloon travels. It goes where the wind takes it.

Blimps have a membrane filled with helium and has a gondola(a basket) with a motor attached to guide it to where you want to go.At one time they were filled with hydrogen (a highly flammable gas)But there was always the danger of this happening

Know this

Rockets and missiles do not produce lift with wings, they counter the pull of gravity bypure thrust.

The compressed air in the bottle forces the water through a nozzle (bottle neck) which produces the thrust required to accelerate the bottle vertically upwards.

Know this

Some Famous Firsts in Flight•400 BCE Chinese invent the first kites •1783 the Montgolfier brothers invent the first hot air balloon•1903 the Wright brothers become the first to successfully fly an engine powered airplane•1927 Charles Lindbergh makes the first solo non stop flight across the Atlantic ocean•1932 Amelia Earhart is the first woman to fly solo non stop across the Atlantic ocean•1961 Yuri Gagarin is the first human to fly into space•1976 the Concorde is the first supersonic (faster than sound) passenger jet•2005 Airbus A380 the world’s largest commercial aircraft ,carrying almost 900 people, completes its first flight

Know two

What are some of the Benefits and Costs ofAviation technology for society and the environment

The speed and ease of air travel allow quick transportation of organs for lifesaving transplants, quick transportation of injured patients to hospitals, and trips for business and pleasure. However, air travel also increases therisk of spreading infectious diseases and creates noise and air pollution.

The use of technology for military use allows for Search and rescue, peace keeping, law enforcement but also provides the ability to be used for war against people with the ability to cause mass destruction

Crop dusting from planes allows chemicals to be spread quickly overlarge crop areas, which is critical to pest control and crop protection. However, the planes cannot control perfectly where the chemicals may go, so the chemicals may spread where they are not wanted affecting plant and wildlife.

Explain one of the pros and one of

the cons of flight from this list or give one of your

own